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Daylight Savings Time

Standard Time

The Earth rotates 15 degrees of longitude in an hour and, in the beginning, there was local time. Each community worked out its own time in relation to the sun. Standard Time grew out of the need to create train schedules so that the trains could run "on time." Standard Time Zones were established which covered approximately 15 degrees of longitude. Arizona is in the Mountain Time Zone. But major population centers, Flagstaff, Phoenix and Tucson, run down the center of the state which means that most of the population of Arizona is clustered towards the western edge of the Mountain Time Zone. Communities on or near the Colorado River are on the western edge of the Mountain Time Zone.

Daylight Saving Time

The concept of Daylight Saving Time can be traced back to Ben Franklin and his calculation that French shopkeepers could save one million francs per year on candles if they would reset their clocks to take advantage of more daylight hours during certain times of the year. The idea resurfaced periodically, usually in times of war and in connection with attempts to conserve fuel.

Daylight Saving Time in Arizona

Although Arizona has observed Daylight Saving or War Time in the past, it currently exempts itself from the observance (A.R.S. § 1-242). However, the Navajo Nation, in northeastern Arizona, DOES observe Daylight Saving Time. The following is a chronology of Daylight Saving Time in Arizona:

31 Mar 1918

Arizona went on Daylight Saving or War Time.
Daylight Saving Time began in the United States.(40 Stat 450) To conserve fuel for the war effort during World War I, Congress passed "An Act To save daylight and to provide standard time for the United States" (65th Congress, Chap. 24, approved March 19, 1918, S. 1854, Public, No. 106) specifying:

Sec. 3. …between the last Sunday in March at two o’clock antemeridian and the last Sunday in October at two o’clock antemeridian in each year the standard time in each zone shall be one hour in advance of the mean astronomical time of the degree of longitude governing each zone, respectively.

Arizona participated in this change but not uniformly. Phoenix, AZ moved an hour ahead of Mountain Standard Time but several communities on the western Arizona border moved an hour ahead of Pacific Standard Time.

27 Oct 1918

Arizona returned to Standard Time.
The United States returned to Standard Time and, in Arizona, Phoenix returned to Mountain Standard Time and the communities on the western Arizona border moved back to Pacific Standard Time.

30 Mar 1919

Arizona went on Daylight Saving Time.
The United States returned to Daylight Saving Time. Again, Arizona participated in this change but not uniformly. Phoenix, AZ moved an hour ahead of Mountain Standard Time but several communities on the western Arizona border moved an hour ahead of Pacific Standard Time.

26 Oct 1919

Arizona returned to Standard Time.
On 20 Aug 1919, the federal law mandating Daylight Saving Time was repealed over President Wilson’s veto because farmers objected to adjusting their work schedules.

Although some states continued to observe Daylight Saving Time until World War II, most of Arizona stopped observing it on 26 Oct 1919.("Clock's Disturbing Alarums to Cease from Troubling Tomorrow." Arizona Daily Star, 25 Oct 1919, p. 6) However, communities in Yuma County observed Pacific Daylight Time from 6 March 1921 until 30 Oct 1921.

9 Feb 1942

Arizona went on War Time.
President Franklin Delano Roosevelt instituted "War Time." Most of Arizona moved to Mountain War Time but a few communities on the western Arizona border moved to Pacific War Time.

1 Jan 1944

Arizona returned to Standard Time.
With the proclamation of Arizona’s Governor, Sidney Preston Osborn, most of Arizona returned to Mountain Standard Time (or Pacific War Time).("Arizona Leaves War Time." Arizona Republic, 1 Jan 1944) However, a few communities on the western Arizona border remained on Pacific War Time. Also, railroads, air lines, bus lines, military personnel and some engaged in interstate commerce continued to observe Mountain War Time because of a federal law enacted 20 Jan 1942.

1 Apr 1944

Arizona returned to War Time.
The 16th Arizona Legislature, during the 2nd Special Session, passed S.B. 3 (Laws 1944, 2nd SS, ch. 7) "Relating to standard time; establishing the standard time for Arizona, and declaring an emergency." The portion of the state within the Mountain Time zone as defined by the U.S. Interstate Commerce Commission was to observe Mountain Time ("solar time of the one hundred fifth meridian west of Greenwich") from 1 October to 31 March and from 1 April through 30 September "the equivalent of mountain daylight saving time" was to be observed. The portion of the state within the Pacific Time zone as defined by the U.S. Interstate Commerce Commission was to observe Pacific Time from 1 October to 31 March and from April 1 through September 30 "the equivalent of pacific daylight saving time" was to be observed. Common carriers engaged in interstate commerce and federal officers and departments were exempt from the law. Since it was an emergency measure, it became effective as soon as it was signed by the Governor on 17 Mar 1944.

Although one source indicated that most of Arizona moved to Mountain War Time (or the equivalent of Mountain Daylight Saving Time) on 17 Mar 1944, the law appears to indicate that the state was to remain on Mountain Standard Time until 1 April 1944 and then cut over to Mountain Daylight Saving Time (the equivalent of Mountain War Time). A contemporary newspaper article ("Governor Signs New Time Bill." Phoenix Gazette, 17 Mar 1944) does NOT indicate that the state was to immediately move to Mountain War Time but that the change would take place 1 April 1944.

1 Oct 1944

Arizona returned to Standard Time.
Most of Arizona returned to Mountain Standard Time and the Mohave County area changed to Pacific Standard Time with the exceptions indicated in Laws 1944, 2nd SS, ch. 7. ("Clocks Turn Back Hour in State Tonight." Arizona Republic, 30 Sep 1944) Laws 1945, ch. 38 (H.B. 149) repealed Laws 1944, 2nd Special Session, ch. 7 and was signed by Governor Sidney Preston Osborn 7 Mar 1945. Since the bill had an emergency clause, it became effective as soon as it was signed by the Governor and Arizona, with the exception of interstate commerce and federal officers, remained on Mountain Standard Time until the mid-1960’s. Mohave County joined the rest of Arizona in moving to Mountain Standard Time.("Standard Time Law Adopted." Arizona Republic, 8 Mar 1945)

30 Apr 1967

Arizona went on Daylight Saving Time.
The Uniform Time Act of 1966 (P.L. 89-387) mandated Daylight Saving Time from the last Sunday in April to the last Sunday in October unless a state opted out. Arizona observed Daylight Saving Time

C. Notwithstanding any other provision of law to the contrary by the United States government relating to adoption of daylight saving time by all of the states, the state of Arizona elects to reject such time and elects to continue in force the terms of subsection A, relating to standard time in Arizona.

An Arizona Republic editorial ("It’s Settled." 26 Mar 1968) noted that "drive-in theaters, the parents of small children, the bars, the farmers and those who do business with California" would be pleased that Arizona would remain on Mountain Standard Time and that "power companies, the evening golfers, the late risers, and the people with business interests on the Eastern seaboard" would be unhappy. Another Arizona Republic editorial ("Why Arizona Should Forget Daylight Saving Time Idea." 10 Mar 1969) noted:

"The above data [sunrise and sunset times and average temperatures during the summer months from the U.S. Weather Bureau] clearly show that we must wait until about 9 p.m. DST to start any night-time activity such as drive-in movies, moonlight rides, convincing little children it’s bedtime, etc. And it’s still hot as blazes!"

The federal Emergency Daylight Saving Time Energy Conservation Act of 1973 (P.L. 93-182, December 15, 1973) established a trial year-round Daylight Saving Time period to start 6 Jan 1974 to 27 Apr 1975. However, 4 Jan 1974, U.S. Transportation Secretary, Claude S. Brinegar, granted a temporary exemption from Daylight Saving Time to Arizona, Idaho and Oregon (Arizona Republic, 5 Jan 1974, p. A1) Rep. Frank Kelley, R-Phoenix believed that the exemption "was prompted by the fact that Arizona is on the western edge of the mountain time zone where the exemption will keep Arizona, California and Mexico on the same time and stimulate business among them." Gov. "Jack" Williams thought that petitions from "vegetable growers, farm bureaus, parents and industrial operations" swayed Secretary Brinegar and that the exemption would permit Arizona "to remain on a clock time more compatible with the sun time." P.L. 93-434, October 5, 1974, amended P.L. 93-182 to restore standard time from November 1974 through February 1975.

In addition to most of Arizona, the state of Hawaii, American Samoa, Guam, Puerto Rico and the Virgin Islands do not observe Daylight Saving Time.